/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.catalina.tribes.io;

import org.apache.catalina.tribes.ChannelMessage;
import org.apache.juli.logging.Log;
import org.apache.juli.logging.LogFactory;

import java.io.IOException;
import java.net.Socket;
import java.nio.ByteBuffer;
import java.nio.channels.SocketChannel;

/**
 * The object reader object is an object used in conjunction with
 * java.nio TCP messages. This object stores the message bytes in a
 * <code>XByteBuffer</code> until a full package has been received.
 * This object uses an XByteBuffer which is an extendable object buffer that also allows
 * for message encoding and decoding.
 *
 * @author Filip Hanik
 */
public class ObjectReader {

	private static final Log log = LogFactory.getLog(ObjectReader.class);
	protected long lastAccess = System.currentTimeMillis();
	protected boolean accessed = false;
	private XByteBuffer buffer;
	private boolean cancelled;

	public ObjectReader(int packetSize) {
		this.buffer = new XByteBuffer(packetSize, true);
	}

	/**
	 * Creates an <code>ObjectReader</code> for a TCP NIO socket channel
	 *
	 * @param channel - the channel to be read.
	 */
	public ObjectReader(SocketChannel channel) {
		this(channel.socket());
	}

	/**
	 * Creates an <code>ObjectReader</code> for a TCP socket
	 *
	 * @param socket Socket
	 */
	public ObjectReader(Socket socket) {
		try {
			this.buffer = new XByteBuffer(socket.getReceiveBufferSize(), true);
		} catch (IOException x) {
			//unable to get buffer size
			log.warn("Unable to retrieve the socket receiver buffer size, setting to default 43800 bytes.");
			this.buffer = new XByteBuffer(43800, true);
		}
	}

	public synchronized void access() {
		this.accessed = true;
		this.lastAccess = System.currentTimeMillis();
	}

	public synchronized void finish() {
		this.accessed = false;
		this.lastAccess = System.currentTimeMillis();
	}

	public boolean isAccessed() {
		return this.accessed;
	}

	/**
	 * Append new bytes to buffer.
	 *
	 * @param data  new transfer buffer
	 * @param len   length in buffer
	 * @param count whether to return the count
	 * @return number of messages that was sent to callback (or -1 if count == false)
	 * @throws java.io.IOException
	 * @see XByteBuffer#countPackages()
	 */
	public int append(ByteBuffer data, int len, boolean count) throws java.io.IOException {
		buffer.append(data, len);
		int pkgCnt = -1;
		if (count) pkgCnt = buffer.countPackages();
		return pkgCnt;
	}

	public int append(byte[] data, int off, int len, boolean count) throws java.io.IOException {
		buffer.append(data, off, len);
		int pkgCnt = -1;
		if (count) pkgCnt = buffer.countPackages();
		return pkgCnt;
	}

	/**
	 * Send buffer to cluster listener (callback).
	 * Is message complete receiver send message to callback?
	 *
	 * @return number of received packages/messages
	 * @throws java.io.IOException
	 * @see org.apache.catalina.tribes.transport.ReceiverBase#messageDataReceived(ChannelMessage)
	 * @see XByteBuffer#doesPackageExist()
	 * @see XByteBuffer#extractPackage(boolean)
	 */
	public ChannelMessage[] execute() throws java.io.IOException {
		int pkgCnt = buffer.countPackages();
		ChannelMessage[] result = new ChannelMessage[pkgCnt];
		for (int i = 0; i < pkgCnt; i++) {
			ChannelMessage data = buffer.extractPackage(true);
			result[i] = data;
		}
		return result;
	}

	public int bufferSize() {
		return buffer.getLength();
	}

	public boolean hasPackage() {
		return buffer.countPackages(true) > 0;
	}

	/**
	 * Returns the number of packages that the reader has read
	 *
	 * @return int
	 */
	public int count() {
		return buffer.countPackages();
	}

	public void close() {
		this.buffer = null;
	}

	public long getLastAccess() {
		return lastAccess;
	}

	public void setLastAccess(long lastAccess) {
		this.lastAccess = lastAccess;
	}

	public boolean isCancelled() {
		return cancelled;
	}

	public void setCancelled(boolean cancelled) {
		this.cancelled = cancelled;
	}

}
